Effect of isoproterenol and acetylcholine treatment in vitro on cyclic nucleotides in mouse sex accessory organs

The effect of treatment in vitro with either isoproterenol or acetylcholine on the levels of cyclic AMP and cyclic GMP in male mouse prostate gland and seminal vesicle was studied. In each experiment, tissues were preincubated with aminophylline (5 mM) for 10 min prior to exposure to the autonomic agonist. Treatment with 1 × 10 −5 M isoproterenol for 5 min resulted in significant increases in endogenous levels of cyclic AMP in both prostate glands and seminal vesicles obtained from intact mature male mice. This effect of isoproterenol on cyclic AMP could be blocked by pretreatment for 10 min with an equimolar (1 × 10 −5 M) concentration of propranolol. On the other hand, isoproterenol (1 × 10 −5 M for 5 min) had no effect on sex accessory organ levels of cyclic GMP. If sex accessory organs obtained from intact mature male mice were subjected to acetylcholine (1 × 10 −5 M for 5 min), significant increases (P < 0.05) in cyclic GMP were noted in the seminal vesicles; this effect could be blocked by atropine pretreatment (1 × 10 −5 M for 10 min). Just as isopro erenol had no effect on sex accessory cyclic GMP levels, acetylcholine produced no changes in cyclic AMP in these tissues. Although treatment with neurotransmitters resulted in striking increases in cyclic nucleotides in sex accessory tissues obtained from normal mice. this treatment had little or no effect on cyclic nucleotide levels in tissues obtained from 7-day castrate mice.